


i could drink a case of you (still i'd be on my feet)

by readythefanons



Series: FE3H A/B/O fic collection [1]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alpha/Beta/Omega Dynamics, Character Study, Emotional Intimacy, F/M, First Time, Kinda, Knotting, Multi, Non-Traditional Alpha/Beta/Omega Dynamics, Omega Felix Hugo Fraldarius, Omega Sylvain Jose Gautier, Other, Penis In Vagina Sex, Smut, Sparring as foreplay, They/Them Pronouns for My Unit | Byleth, Vaginal Fingering, alpha mercedes von martriz, beta byleth, if you need me i'll be in my dumpster, lady alphas fuck yeah, little bit of spanking, sylvain please go to therapy, that's a felix tag obviously
Language: English
Status: Completed
Published: 2020-08-24
Updated: 2021-02-02
Packaged: 2021-03-06 21:26:50
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 9,714
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26075629
Author URL: https://archiveofourown.org/users/readythefanons/pseuds/readythefanons
Summary: The Blue Lions house had three omegas, but very few outside the house knew it. Suffice to say, neither Felix, Ingrid, nor Sylvain found any interest in it as a topic of conversation.Byleth, a beta, didn’t so much as blink when they learned which of their students were omegas, nor did they evince any reaction when informed the house’s sole alpha was Mercedes.The only time Byleth was less than calm was when they learned how the omegas managed their heats. Rather than making use of moon tea, they made use of—cruder, more natural means. An incipient heat could be prevented if the body was subjected to sufficient stress. This was obviously part of the body’s own set of survival mechanisms, andnotintended to be treated as a convenient quirk to be exploited.In short, Byleth hit the roof when they found out what Felix, Sylvain, and Ingrid were doing to themselves… And then it precipitated that of the omegas, only Ingrid had ever experienced even a modified heat.Well, shit.==Blue Lions A/B/O ficlets, which can be read standalone.Ch1: o!Felix/b!Byleth, sparring as foreplay, and also sexCh2: o!Sylvain/a!Mercedes, little bit of spanking, lots of Sylvain baggage, and also sex
Relationships: Felix Hugo Fraldarius/My Unit | Byleth, Sylvain Jose Gautier/Mercedes von Martritz
Series: FE3H A/B/O fic collection [1]
Series URL: https://archiveofourown.org/series/2120154
Comments: 4
Kudos: 58
Collections: FEOmegirlverse 2021





	1. (I could drink a case of you) still I'd be on my feet - Felix/Byleth

**Author's Note:**

> *crawls out of dumpster*  
> Listen, I wrote down everyone’s names, rolled some dice, and used that to assign ABO designations. The universe has spoken.
> 
> Everyone has a penis and vagina. Alphas undergo rut, betas undergo rut and heat (and have a changeable profile depending multiple factors including social network), and omegas undergo heat.
> 
> Brief discussion of various forms of self-harm as a means of suppressing heats in ch 1.

**Summary for the Chapter:**

> Felix/Byleth  
> =  
> If Felix had to experience heat, and if he had to have “a first time,” he wanted it to be similar overall to practicing the sword. Byleth obliges.
> 
> _Sparring with Byleth today, with his blood thick with hormones, was absurdly good. They fought, blade against blade, blood singing in his veins, until Byleth disarmed him with one elegant motion, kicked his legs out, and stood over him, sword point under Felix’s chin._
> 
> _“Okay,” he said, voice and breath ragged, “I’m ready.”_

**Notes for the Chapter:**

> This chapter: AU where everyone’s college age and Byleth is more of a peer mentor/not actually anyone’s professor somehow, idk I’m not a superfan of student/teacher stuff and just wanted to type something ¯\\_(ツ)_/¯
> 
> nb!Byleth uses they/them pronouns

The Blue Lions house had three omegas, but very few outside the house knew it. Suffice to say, neither Felix, Ingrid, nor Sylvain found any interest in it as a topic of conversation.

Byleth, a beta, didn’t so much as blink when they learned which of their students were omegas, nor did they evince any reaction when informed the house’s sole alpha was Mercedes. Points to the outsider. Returning courtesy with courtesy, none of the Blue Lions commented when Byleth’s scent shifted, becoming even more alpha-esque than even Dimitri, who passed so well he was often outright mistaken for alpha.

The only time Byleth was less than calm about anything related to the matter was when they learned how, specifically, the omegas of the house managed their heats. Rather than making use of moon tea, to take the edge off and dull the effect (the safest and most widely used option), or even twilight or midnight tonics to shorten the duration (effective but uncomfortable, generally used for last-minute prevention), they made use of—cruder, more natural means. Simply put, it was a biological fact that an incipient heat could be prevented if the body was subjected to sufficient stress. Blood loss, any sort of injury precipitating shock, extreme fatigue, dehydration, insufficient caloric intake, or “the right kind” of poisonings could all stop a heat dead in its tracks. This was obviously part of the body’s own set of survival mechanisms, and _not_ intended to be treated as a convenient quirk to be exploited.

In short, Byleth hit the roof when they found out what Felix, Sylvain, and Ingrid were doing to themselves, and the omegas shouted back just as loudly that they’d been doing this for years already and it was working for them. It took a long time for the dust to settle and feelings to be untwisted, but—well. It’s not like pushing yourself to the point of passing out, picking fights and then blackout drinking, and denying oneself food and water to the point of illness on a regular basis was _enjoyable._ So Byleth “won” that argument. Didn’t feel like much of a victory, _maybe_ like the prevention of compounding loss.

And then it precipitated that of the omegas, only Ingrid had ever experienced even a modified heat. 

Well, shit.

* * *

If Felix had to experience heat, and if he had to have “a first time,” he knew he wanted Byleth as his partner. They were very, very strong, and they were patient, and they were not overly prone to getting emotional and flapping around like some stupid bird and making their emotions Felix’s problem. And (and Sylvain and just about everyone Felix knew would make fun of him for this, but shut up) there was the way were in the training yard. 

The first time he’d crossed blades with Byleth, Felix hadn’t been expecting much. He’d crossed blades with knights and swordmasters, and all manner of professionals, and Byleth the same age as Felix himself. People his age who fancied themselves skilled were the most annoying of all. But Byleth had been good: competent, almost eerily calm. They’d had matched him, blow for blow, and disarmed him in one devastatingly efficient motion. When he’d demanded another round, Byleth hadn’t smirked or hesitated or smiled patronizingly—they had just nodded. When he’d told them to come at him hard, they had. When his muscles were twitching and jumping from overuse and he’d asked for another bout, they’d obliged. Byleth was eerily observant, probably knew his limits better than he did, but they never, ever coddled him. Felix had learned the hard way that when Byleth voiced the opinion that the two of them should ease up, it was smart to listen, and if Felix insisted Byleth would give. (When Felix, waking up on floor of the training yard after _passing out_ had asked why they hadn’t just forced him to stop, they had said, ‘I wouldn’t let you be harmed, and there was a chance you would succeed.’) 

For something like _this,_ he trusted Byleth. 

Of course, Felix was only human. He thought about it a lot before he made his move—one could even say he worried over it, if one wanted to die by Felix’s blade. But Felix had been forbidden from preventing his heat the way he normally did—and, if Felix was honest with himself, his normal approach was really not good for his body, and the twilight potion made anyone who took it feel terrible, and the midnight potion was also quite bad for you, and there was a slim chance that _this_ would be better. Plus, it was likely that he had to have a heat eventually. So he decided. It would be cowardice not to at least try, and he was no coward. So—he asked. And Byleth agreed.

Byleth was a strange individual, absurdly ignorant about fundamental aspects of life in Faerghus (Utterly unfamiliar with the Goddess’s scriptures, couldn’t name all four Saints, and didn’t even know they bore a Crest on their own body? How.) but they did have areas of deep and impressive competence. Swordfighting was one, battlefield tactics (though perhaps not strategy) was another, and apparently planning what Sylvain (and Annette, for some thrice-cursed reason. Why.) referred to as “sexcapades” was one as well. Why, Felix knew not.

Felix shouldn’t really complain though, as he was benefitting. Byleth had somehow secured a private training yard within the monastery. It was warded from the foundations to the eaves, making it not just a private training yard, but an extremely private training yard.

It got better from there, because Byleth also brought their weapons.

“Training or steel?” they asked. Felix considered. He was feeling a little off, a little overheated and jittery, but the prospect of practicing with live steel was always satisfying, and today it was a little, uh, stimulating as well. Hm. 

“Do you have vulneraries?” he asked. Byleth gestured, and Felix saw a line of bottles set along the wall. A set of vulneraries, a set of concoctions, and not one, but two, elixirs. Sweet merciful Cethleann. Plus a standard field medic’s kit, and some sort of mysterious bundle that Felix suspected contained, like, extra clothes or a blanket or something. “Steel,” he said. Byleth nodded. The two of them drew their blades and squared off.

Felix loved sparring. It was satisfying in almost every way. It calmed his mind, it exercised his body, and it made him feel like he was making progress towards a greater purpose. Sparring with Byleth was even better, somehow, because it made him feel—like there were people out there, of common mind, who understood that he loved the burn, the weariness, the little pains that were the reward for a fight well fought. 

Sparring with Byleth today, with his blood thick with hormones, was just absurdly good. They fought, blade against blade, blood singing in his veins, until Byleth disarmed him with one elegant motion, kicked his legs out, and stood over him, sword point under Felix’s chin.

Oh, it was good. Felix felt hot, his heart was pounding, every part of him felt incredibly, searingly alive. Byleth’s blade was steady and unyielding, and Felix was so, so wet. Of course he was, all the energy and rushing blood and sheer _aliveness,_ of course he was wet.

“Okay,” he said, voice and breath ragged, “I’m ready.”

“You don’t want another round?” Byleth asked mildly, sheathing their sword. Another wave of arousal rolled through Felix. He did want another round, yes, but he was already prickly-aching-hot for this new thing. If he got any more wet, he’d probably soak through his clothes. Byleth continued, “We can, you know. Probably better to switch to training swords, or unarmed. Or we can skip it.”

“Unarmed,” Felix said. Goddess, yes. 

The match was really not a match at all, just overt foreplay. By the end, Byleth was just holding him down, kneeling over Felix, wrists pinned by his head and body carefully pressing against him. Felix writhed for the sheer satisfaction of feeling how securely he was held, and Byleth kept him in place with ease. Felix struggled to break free, felt the slickness between his legs grow when it proved impossible, and let his head fall back on the ground. Byleth, warm and alive and satisfyingly strong, was breathing heavily above him, but they weren’t panting anywhere near as hard as Felix.

“Okay, _now_ I’m ready. Take me.” It was the same way he normally demanded another round, and Byleth looked at him levelly and nodded, the same way they normally acquiesced. Someone else might want kisses and gentle touches, but Felix’s blood was _hot_ in his veins and he neither wanted nor needed that sort of sticky sweetness. Byleth adjusted their hold, shifting to the side but keeping one hand on Felix’s wrists, and slipped the other past his waistband. Felix panted as Byelth’s fingers gently brushed his opening, confirming just how slick he was. Felix’s cheeks were red, but neither of them acknowledged it. Byleth didn’t push in, just traced the slick folds, and Felix growled.

They looked at him levelly, not smug or disdainful or any other stupid thing, just assessing. Felix met their eyes squarely, impatient, and Byelth nodded. They pressed one finger in, and he gasped at how smoothly and easily it went in. Felix was fairly sure he’d never been this slick before, and he’d never done this with another person before (had rarely done it by himself), but the feeling was—good. It was good, but strange, and his body accommodated the intrusion so easily it—almost made it a stranger to him. His next breath shook, just slightly, and his cheeks were burning.

Byleth shifted, pressed their body more firmly against Felix, slid their other hand up so instead of pinning Felix’s wrists they were—securing his hands, fingers tangling together. Felix breathed through the strangeness of the moment, the promise of pleasure and his own wariness. Byleth waited, and watched, and didn’t rush him. Felix breathed, eyes closed, until he could breathe with his eyes open.

“Good,” Byleth said when Felix met their eyes again. Simple, honest, factual, like when he got a new combination exactly right. Felix’s body—reacted to that, fluttered around Byleth’s fingers, and he blushed, but Byleth didn’t acknowledge it, just started stroking their fingers in him. “This amount of slick is well within the standard range for a healthy omega undergoing heat,” Byleth informed him in exactly the tone they used when sharing information about a new training exercise. It was familiar and grounding. “It’s a sign that you’re in good condition.” Felix nodded, and they nodded, and that was that.

Byleth fingered him with care and attention, not because they wanted anything from him—his undeserved submission or his hypothetical passion—but because Felix wanted to know and understand this. They went slowly, not out of tenderness but out of practicality, which made Felix feel unbelievably comfortable. He hated being coddled and suspected that, in this context, it wouldn’t have been able to bear it. “I suspect you already know,” they said conversationally, “but around here” and pressed—and pleasure seized him like a fist, drawing his muscles taut and punching an unsteady groan from his lungs—“tends to be especially sensitive.” _Oh, oh,_ no, Felix had not known that already. He was panting, and every exhale wanted to turn into a, a moan. Oh, wow. He, oh.

Byleth stopped stroking that spot. “Breathe,” they said, calm and implacable, and Felix did. He breathed, and he _was_ moaning, quietly, but—he peered at Byleth through slitted eyes and they looked just as calm as ever—and he breathed, and if he moaned too, well, that was fine. No one here was going to think less of him for it. When Felix felt present again, Byleth said, “Good.” Simple, honest, factual. Felix groaned his way through his body’s reaction to that, and it _was_ good.

“I’m ready,” he said at last. “Fuck me.” Byleth nodded.

“Do you want to undress?” they asked, and hm there was an idea. Felix nodded, and each of them proceeded to strip off their clothes with satisfying efficiency. Byleth produced a blanket and, at Felix’s nod, laid it in the middle of the training yard. (Again, just about everyone Felix knew would laugh themselves stupid for the location, but they weren’t here and could shut up and stay shutted up.) “I would prefer it if we were facing each other,” they said, and that was fine with Felix, “Do you want to lie down or should I?” Felix—hadn’t thought about that possibility. He’d just assumed that, as the omega, he’d be the one pressed to the ground, his partner looming over him, situationally forced into an uncomfortably vulnerable position (although with Byleth it wouldn’t be too bad, might even be good, delicious to have all that strength bearing down on him), but—it was his first time (ugh he hated the sentimentality that attached to that phrase), and the whole situation was so new.

“You lie down,” Felix said. Byleth nodded and complied. Felix took a moment to admire the view. Byleth was a shade or two darker than Felix himself, and well-muscled just about everywhere. Their erect cock jutted up, and it was—big. Now that Felix was, figuratively speaking, face-to-face with it, he was aware of how Byleth’s cock was much larger than their fingers had been, thicker and longer. Goddess and all Saints.

“It wasn’t always like this,” Byleth said with the first hint of embarrassment all day. “It’s—your class. Dynamic socio-phermonal beta presentation at work.” In other words, being in the omega-rich environment that was the Blue Lions had triggered a hormonal response that had pushed Byleth’s beta-body to present more like an alpha. Felix’s own body felt a glow of—satisfaction at the words, the implication that his, his classmates’ own need had called to their new companion and had been answered. The—sensation was distinctly strange.

“Works for me,” he said, and resisted the urge to press his legs together in hopes of hiding his renewed wetness. They nodded, still looking sheepish, and Felix decided it was time to get on with it.

He straddled their waist, took them in hand. Byleth’s hands found his waist, warm and strong. “Don’t rush,” they reminded him. “Breathe.” He nodded, took a deep breath. 

He lowered himself onto their cock, breathing through his own reaction to the blunt head, the thick shaft. It was—big, very, very big, or so it felt. Byleth’s fingers had been easy, but their cock stretched him, pushed him open. “Breathe,” Byleth said, and Felix breathed. His body was shaking slightly, _tight_ around Byleth’s cock, and oh, it was so—satisfying. Felix was breathing in the space between good and too much, his body both wanting more and complaining about the girth. Oh, it was so much.

“Breathe,” Blyeth instructed, and he breathed. “Slow down, don’t rush,” Byleth said, and Felix slowed, but he didn’t stop. It hurt, a little, and he was chasing that edge. He was pushing himself, he always did, and he loved the feeling of pressing right up to his body’s limits and then pushing a _little_ more. His body was adjusting, stretching, accepting the intrusion, and he breathed as he sank lower and lower on Byleth’s cock. Goddess, it was big. He sank all the way to the base, felt a kind of shock when he was finally seated. He felt impossibly full, and glad that Byleth’s hands were moving on his hips, stroking him with calm, warm hands, offering a simple counterpoint to—this.

“I need to feel it,” Felix panted, and his voice was strange, and his body felt strange, and he was so, so full. Once, they had been demonstrating a particularly nefarious arm lock on him, and they’d said _feel this,_ and waited. Felix had felt it, the way the move worked, in his own body, in the tension and pull and hypothetical threat, and he’d learned from it more easily than reading a description in a book or watching a demonstration from the outside. In the here and now, Byleth waited, and Felix waited, and felt it, and let his body work itself out. 

“Take your time,” Byleth said, “Just feel it and breathe.” Felix nodded (the motion just barely wobbly), and sank into it. He breathed in and out and felt the stretch of his body around that cock. He breathed in all the ways it could hurt and all the ways it could satisfy. And when he started to learn, he nodded to Byleth.

“Now. Move,” Felix ordered. Byleth moved, and the process started over. Felix taught himself not just what this act was like, but how his body reacted, what made it ache and made it melt.

In the same way Byleth let him spar until his muscles were barely cooperating, they let him find and push his limits here. They took him right up to the edge of bearable when he demanded it, fucking him hard and fast while he braced himself on their shoulders. Oh, it was so satisfying. He was moaning, not the high submissive whines of the omega stereotype, but guttural and heartfelt and—still demanding, still full of need, and satisfied too that he was getting everything he asked for. The physical sensation was too intense and too complex to be simply _good_ , but it was perfectly satisfying and Felix understood why people might make themselves fools for this. 

Everything built, and when it started to overwhelm, Byleth set their hands on his back. _Breathe,_ they reminded him, and he did. Everything he wanted to take, they gave him. Felix knew how to weather pain, but he didn’t know what to do in the face of such acute animal pleasure. He was learning. It started to become too much, too good, too bright and overwhelming, again, and Felix tangled a hand in his hair, pulled hard to feel the pain, caught Byleth’s gaze.

“It, I don’t want to stop, but—” he gasped out, felt the wildness in his own expression. Byleth, Goddess bless and preserve them, seemed to understand. One hand settled on his hip, firm and grounding, and the other reached up, offered an open hand. It wasn’t grasping or pleading, just offering.

“Breathe,” they said, “Feel this. It’s not—I know you can, if you let yourself, if you’re ready.” Felix untangled his hand, left his hair alone, put his hand in theirs. He let himself feel how good it could be, to be filled, to be fucked. Instead of trying to stay above it (through stubbornness and avoidance) or go around it (through pain and complexity) he let it wash through him. It bowed his back, bent him forward until he was pressed against Byleth’s chest, crying out, clutching their hand. It was impossibly good, and Byleth remained steady and stable and patient, rolling their hips through it all. Their free hand stroked his back and sides, and they reminded him to breathe, and Felix let himself feel it, take it, feel it all until, instead of avoiding the storm, he came through to the other side. He lay on Byleth and breathed, breathed, breathed and it was so easy. Byleth stroked a warm hand over his back.

“More,” Felix said at last, pushing himself back up, and Byleth did smile now.

“You sure?” 

“Knot me,” Felix said, uncaring of how his cheeks reddened. “I’m ready.” Byleth breathed, in-hold-out-out-out.

“I,” Byleth said, and hesitated, just for a moment. “It will happen all at once, I can’t control the, the speed.” The knot, they meant, knots formed fast and hard. Byleth valued self-control above all else, and Felix didn’t know if the stammer was revealing how intensely they were experiencing this in spite of their exquisitely controlled (precise, measured, perfect) motions or their degree of discomfort in not being able to control—that. Felix felt an emotion well up in him, that they were each trusting the other, just for a moment before he pushed it away.

“Fine,” Felix said, and he ground against them. His body was used to this already, used to the stretch, and if he knew there was more—another layer of intensity—why wouldn’t he chase it? Byleth groaned, very quietly, and it stoked the fire already burning Felix from the inside out. “You—should we stay like this? Or. We could switch,” he found himself saying. If he was hoping for an obvious reaction, he would have been disappointed. Byleth only stroked his hip and looked at him with clear eyes. 

“Your choice,” they said, and Felix groaned, rocked his hips and felt how easily his body was accommodating the cock inside him. Felix’s choice. Fine.

“Switch places with me,” Felix demanded. Byleth nodded, raised a brow almost imperceptibly and did—something, some movement that resulted in Felix lying on his back, Byleth kneeling between his spread legs, cock still seated within him. Felix expressed his surprise and interest in learning such a move himself in the form of a heartfelt moan. Byleth’s cock didn’t breach him quite as deeply like this but that was—fine.

“Okay?” Byleth asked, and Felix blinked open his eyes (when had he closed them?), nodded. Byleth was leaning over him now, looking him in the face. He expected to dislike this intimacy, being spread open beneath another body, expected to have to learn the boundaries and edges of the feeling, but—oh, finally, something about all this was simple. He liked it. Byleth was strong and warm and familiar, and Felix found it easy to loop his arms around his companion’s shoulders, tug them close enough to feel them breathing. 

“Good,” Felix said. “When you’re ready.” Byleth fucked him, a little, let Felix feel what it was like to be filled in this position, then breathed in-in-hold-out-out-out. They pressed their mouth to the corner of Felix’s jaw, and then— _oh_. 

The knot was big. Felix was already fuller than he’d ever been, but the knot was something else. Byleth was half-pulled out, so the thing only pressed Felix’s rim, but _oh_ , there was the stretch. Felix’s neck arched, his back arched, his hips tipped to take in more, more, more, and he was distantly aware that his moans were _loud_. Goddess and all Saints. Byleth pushed in, glacially slow, and Felix moaned, loud and heartfelt, and felt his body just—take it. Goddess.

Okay, _now_ Felix was impossibly full, and by rights it should fucking hurt, and it kind of did, but it was all lost in the, the rush. It was very much like when Felix was exercising and his mind and body did a, a thing, and he felt the same rush, the same intoxicating mixture of pain and satisfaction, the exquisite overlap of _not sure I can take this_ and _can’t bear to stop_. And somehow, in the here and now, Byleth was there, giving this to Felix, and from their groans Felix just knew they were riding the absolute knife edge of control and desire. It should have been frightening, to have his body at the mercy of someone so strong and so close to the edge, but Felix Hugo Fraldarius wasn’t afraid of _Byleth_. It was delicious, the same stomach-drop moment of fear and confidence he got when he stepped into the ring to face the merciless glint of steel, and it went on and on.

Felix was coming, uh, a lot. For a long time. And Byleth—cool, implacable, calm Byleth—was groaning, low and quiet and insanely hot as they fucked into Felix’s body, stretching him with that ridiculous knot.

“Fucking _come_ —” Felix eventually managed to choke out. “Now, in me, now, _Byleth—_ ” Byleth did, their mouth pressed firmly to the column of Felix’s neck and ordinarily that would be far too intimate but, well, context, and also Felix’s arms were threatening to fall asleep from how tightly they were wrapped around Byleth’s shoulders, and it was just possible tat Felix’s own face was pressed tightly against the side of Byleth’s neck, so all’s fair and so on. 

They subsided. They were breathing together, not in unison but in harmony, their chests pressed together as they sucked in greedy lungfuls of air. Felix was discovering new echelons of tiredness, his body heavy with satisfaction and hard use. Oh, yeah, he was gonna pass out.

He did, and he woke up, and Byleth was still inside him and was looking at him with care but no alarm, and Felix was still warm and barely sticky so he couldn’t have been out for long. He blinked at Byleth. Byleth tucked a stray lock of Felix’s hair behind his ear and said, “Good?”

Felix barked out a laugh, shuddered pleasantly when that… jolted him, and said, “Yes.” Byleth looked a bit dazed, which was something to note. They recovered quickly though. 

“Good,” Byleth said, smoothed another bit of Felix’s hair back. Ordinarily Felix would find such an action pointless (his hair was surely an impossible tangle at this point) but here and now he found he didn’t mind. “I hoped so, but it’s important to check.” Felix huffed another ghost of a laugh, shifted his leg, enjoyed another shuddery aftershock, barely managed to keep his eyes open enough to see Byleth’s eyelids flutter. Interesting.

“What now?” Felix asked. (He could hear his friends’ voices making fun, carrying on about pillow talk and sweet nothings, ugh, shut up.) Byleth was unfazed.

“We’re stuck like this for a little while, and then food, water and rest. Depending on how tired you are, water, rest, and then food, but rehydration is very important at this stage.”

“Makes sense,” Felix said. Byleth was still touching his hair, not coddling and fussing, just—touching, with no ill intention, and Felix was surprised by how much he liked it. He asked if this was another hormonal thing, and Byleth agreed that it probably was. Felix untangled one arm from its grip on Byleth to toy with their hair, and Byleth nearly purred. Well alright then.

They separated, and Byleth swept Felix up into a two-armed hold, and Felix graciously did not attempt to maim them, and instead Felix helped Byleth by grabbing the blanket off the ground. Byleth carried him to the side of the training room and settled Felix on the blanket and passed him some water. It tasted amazing. Felix drank a lot, ate a little, fell asleep. When he woke up, Byleth was there, of course, and Felix permitted them to comb his hair while he devoured cold meat, cheese, and fruit that they had stashed somewhere. They ate and drank and let the moment breathe through them, and when it was time to go, they went. This feeling—to be companioned but not pressed upon, to ask and be answered, to hunger and be filled, and to share an experience and let it end—was the most satisfying thing Felix could imagine.

Byleth accompanied him to his room, and Felix turned to say—something, and found Byleth already looking at him, calm and knowing. Felix got the notion that he didn’t need to say a word, but he chose to speak his thanks, and he took their hand, squeezed, and let go.

**Notes for the Chapter:**

> if you enjoyed the general mood/feel of this fic, you may enjoy [with care and attention](https://archiveofourown.org/works/25233817) which is Yuri/Byleth. _Byleth was not an amazing kisser—she didn’t take his breath away or do obscene things with her tongue—but she was competent, and she kissed Yuri exactly the way he wanted to be kissed. She filed away his likes and dislikes for this in the same way she’d learned everyone’s hobbies and favorite blends of tea._


	2. (you're in my blood like) holy wine - Sylvain/Mercedes

**Summary for the Chapter:**

> Mercedes’s room was modest in size but warmly decorated. The whole mood as she guided him into her space was already different from Sylvain’s past conquests—Sylvain had never banged a nun in a church before, except that one time—but the contrasts didn’t end there. He was no stranger to being undressed, but normally it was frantic or hurried or intent. Sometimes the girls didn’t even bother, just worked his pants open and went from there. Mercedes undressed Sylvain slowly. She smoothed her hands across each newly bared expanse of skin as softly as if she was laying a blanket over a lover. She eased his clothes off and touched him gently, matching her hands to the contours of his body as if he possessed some complex form she wanted to learn.

**Notes for the Chapter:**

> Hey, Sylvain, you want some more emotional baggage? No? Well, too bad <3  
> Ahem, less flippantly. In! This! Chapter! After the war! Brief and nongraphic reference to sylvain’s shitty childhood, Sylvain/Mercedes, first times, some spanking, penis in vagina sex.  
> *checks notes* also I use the words cunt and cock a lot. Also whore and slut because Sylvain... doesn't have an amazing relationship with sex in general much less sex work :|

A fact about Sylvain: he has never experienced a true heat. When he was a kid (too young, younger than he should have been for reasons that didn’t bear examination) and the first signs started to appear, the intrusive thoughts and restlessness, he decided, _No._ He would not, could not, be the heir, the secondborn, the Crest-bearer, _and_ an omega. And—if he couldn’t do anything about being an omega (and he couldn’t), he could at least make sure no one found out.

He almost died. A child, a bottle of alcohol, and a winter storm are a dangerous combination without hormonal changes in the mix. But Sylvain didn’t die, and the physical stress of almost dying shut down his oncoming heat, and this Sylvain considered to be a success.

Almost a success. Sylvain suspected his brother knew what had driven him out into the cold. Miklan was already pretty mean to him, but he was meaner after that. Sylvain was disinclined to talk about any of this, ever, with anyone, but even if he wanted to speak of it, all he’d be able to say was—there was an extra edge to Miklan’s cruelty after that.

A fact about Mercedes: she was an alpha, and no one ever wanted to believe it. She understood, even if she didn’t sympathize. It went against people’s preconceived notions of identity. Mercedes was a woman, she’d been raised in a church, she was quiet and liked to bake. She preferred feminine clothes and kept her hair long and loose and even put a bow in it. Therefore, of course people were taken aback when they realized she was not a picture-perfect omega commoner girl. People, sadly, were stupid.

Mercedes scrimped and saved, selling her baked goods and her smiles, to afford the Kingdom School of Sorcery. When she was there, she met Annette, her Annie, and it was finally—Annette was Mercedes’s best friend, this tiny beta girl with her firecracker hair and whirlwind energy. She was the first person who, when Mercedes mentioned taking time off for her rut, only nodded. 

“Oh, you’re an alpha. I wasn’t sure, but you’re always taking care of people. I’ll take notes for you while you’re gone.” 

People, as a category, were stupid. Individuals were worth loving. 

Sylvain liked girls, he really did. Well, no. Sylvain liked having sex with girls. And they made it so easy for him, especially the commoner girls. Commoner omega girls especially threw themselves at him. (Commoner omega boys… they tried, but he had to put a stop to that, for reasons that were less about his preferences and more about—nothing, it was about nothing.) It was funny, they looked at him and saw his Crest and his nobility, and their imaginations filled in the alpha indications that weren’t there. Sylvain held his true status close, his own private joke on the world.

* * *

Sylvain found Mercedes after the war. It wasn’t hard; he knew the name of the church where she’d settled down to work.

“Sylvain,” she said when he darkened her door. She was sitting at a heavy wooden desk, writing in an account book of some sort. “Welcome. What brings you here?” Without waiting for an answer, she sprang into motion, busying herself with her guest’s comfort. Before he could object, he found himself divested of his riding cloak and gently but inexorably guided to a padded chair. A cup of tea steamed gently before him, the unmistakable scent of bergamot brightening the air. “That’s better. Now, what brings you here?” 

“You, actually,” Sylvain answered. “That is—I was hoping to see you.” While he hesitated about how to go on—despite having prepared something of a speech on his way here—she settled not in her own chair, behind the desk, but in the guest chair next to him. She watched him solemnly, clearly not bothered that he was making her wait while he tried to order her thoughts. “I… hear you help people in need now,” was what ended up coming out of his mouth. Mercedes remained unflustered.

“Are you in need, Sylvain?” she asked. Sylvain scrubbed his hand over his head, sighed.

“Something like that,” he admitted. It had been—his body believed it was _supposed_ undergo regular fertility cycles. The means by which he’d been suppressing them were, in their way, brutal. It was worth it to Sylvain, but now—it was starting to not work, and Sylvain could only escalate so much without putting himself in real danger. But, if he understood the books he’d read in secret, allowing his body to undergo a few unhindered cycles should reset him back to baseline, and he could go back to what passed for normal. He did his best to explain without so much as alluding to the means by which he’d been preventing his heats. From the look on his friend’s face, she was filling in the blanks on her own. That wasn’t surprising; she was a healer, and her life hadn’t exactly been a bed of roses even before her training. It was strange and not at all comfortable to see her sorrow and know he’d put it there, just by being himself, but it wasn’t unfamiliar either. Sylvain was kind of an expert at hurting his friends with his personality and habits. “...So, will you help me?” he finished.

She reached out and took his calloused hand in her warm one. Her grip was strong, a friend’s clasp, a comrade’s. Sylvain squeezed her fingers. Then she shifted her grip, wrapping her smaller hand around his fingers, brought his hand up to her lips. She kissed his roughened knuckles, eyes solemn as she looked at him.

“I’d be honored to help,” she said. The simple words, from another person, might have been merely noise, but from Mercedes they made Sylvain swallow and nod. She kissed the back of his hand again, held it lightly and warmly in both of hers. “Now?”

“Well, not _now_ now, but when it’s convenient—” Because of the way Sylvain managed his cycles, they weren’t so much _cycles_ with an active and quiescent period so much as—always trying to happen. Technically, now was as convenient as next week or next month.

“Now is fine,” Mercedes said, gently and immovably. She shut the account book that was still open on her desk, tidied the tea things, and stood before him with both hands outstretched. Faintly amused, Sylvain allowed her to tug him out of his seat and lead him through the halls. She had to have some idea of how often he’d been the one kissing ladies’ hands and leading them to his bed—although generally there wasn’t a _great_ deal hand kissing, not with the girls Sylvain attracted.

Mercedes’s room was modest in size but warmly decorated. Warm brown and goldenrod were the primary colors, but deep Kingdom blue was in evidence everywhere, each splash of color like a glimpse of an old friend. The whole mood as she guided him into her space was already different from Sylvain’s past conquests—Sylvain had never banged a nun in a church before, except that one time—but the contrasts didn’t end there. He was no stranger to being undressed, but normally it was frantic or hurried or intent. Sometimes the girls didn’t even bother, just worked his pants open and went from there. Mercedes undressed Sylvain slowly. She smoothed her hands across each newly bared expanse of skin as softly as if she was laying a blanket over a lover. She eased his clothes off and touched him gently, matching her hands to the contours of his body as if he possessed some complex form she wanted to learn. She didn’t kiss the muscles of his chest, the swell of his shoulders, or even Sylvain’s (if he said so himself) outstanding abs, just touched him gently and moved on. Each touch left a curious warmth in its wake. 

“Are you using magic on me?” he wanted to know. She tilted her head, hands warm on his bare calf.

“I would never use magic on you with asking first,” she said, “Unless it was a matter of life or death, and there was no way to wait for an answer.” He didn’t know what do with that.

“It feels warm,” he said. 

“That’s just me,” she said, smiling at last. He smiled back. “I’ve always had warm hands.” 

When Sylvain was bare, Mercedes started to remove her own clothing. Sylvain roused himself enough to stand, repaid the favor by helping her out of her clothes. He kissed her shoulders, her breasts, her belly and the tops of her thighs, her breasts, and even her ankle. And her breasts. Mercedes laughed a little, the sound too quiet to be a giggle, as he kissed them. She had—not to be, well, himself about it—fantastic breasts. She cupped his cheek, guided him up. He kissed her cheek, the tip of her nose, and finally her mouth. It felt—it felt nice, warm and comfortable, but not terribly _sexy._ Kissing Mercedes, even with her fantastic breasts pressing against his chest, felt more like sinking into a hot bath at the end of a long day than it felt like a prelude to sex. Shit.

Sylvain had picked Mercedes because she beautiful and kind and understanding—and by ‘understanding’ he didn’t mean ‘nice.’ She understood Sylvain in a way that should have been terrifying but never quite was. She understood him in a way that almost hurt, sometimes, like stretching a limb after keeping it tensed for a long time hurt, like blood pushing its way back to deadened extremities hurt, like nerves waking up hurt. And he had picked her because—she liked him, somehow, despite understanding him.

But Mercedes preferred to be nice as well as kind, and that—what was Sylvain supposed to do in a nice girl’s bed? He could kiss her fingertips and call her princess, but she didn’t really seem like the type, and he wasn’t here for—for that, for fucking another girl.

“What’s wrong?” Mercedes asked, hands still holding his face. Sylvain tried to pull away but she didn’t let him, yet.

“Nothing,” Sylvain lied, and he knew he was caught when she pursed her lips ever so slightly.

“Sylvain. Please speak to me,” she said. “The truth, please.” Now she did let go, the room’s air cool compared to her skin, and Sylvain staggered back, sat on the edge of her bed. She sank to her knees next to his feet, looking up at him, and—that was all wrong. 

“I…” _I don’t think this is going to work._ Sylvain couldn’t say that. Not only would it be rude—not to turn down some girl, but to ask his friend for a favor and then back out—but if this didn’t work, he didn’t have a lot of options.

“What do you need?” Mercedes asked when he remained silent. Need. Sylvain could almost laugh.

“You don’t need to be so sweet about it,” was what ended up coming from his mouth. “I’m not exactly a rose petals and candles kind of guy, even if I am—” _an omega._ He wasn’t sure he’d ever said it aloud before visiting her today. He gestured at himself instead. “I’m still the same person.”

“You are,” Mercedes agreed from her spot on the floor. “If you’re asking me to puff myself up on alpha-ness, I can.” Even with her short hair, even stark naked with her fantastic tits out, she radiated sweetness. Sylvain covered a smile. She tilted her head, blinked up at him with an earnestness that had to be exaggerated. “I can.” She stayed there, perfectly still. When Sylvain figured out she was waiting for him, he gestured to her. _Go on._

Her economy of motion was impressive. It wasn’t aggressive, it was just very, very decisive. One second, Sylvain was sitting on the edge of Mercedes’s bed with her kneeling by his feet, and the next he was on his back, his legs on either side of Mercedes. She was leaning over him with her hands braced on his shoulders. “Yes?” she asked. Sylvain swallowed.

“Yes.” If nothing else, he had to see where this went.

Where it went was more kissing. It was still—Sylvain needed to work out some synonyms or something. It was still sweet in a way, but it was hotter, deeper, more carnal. Sylvain could have sighed with satisfaction when Mercedes pulled away to nip at his jaw. For reasons that did not bear examination, Sylvain felt much more at home when there was a nonzero chance his bedmate was going to draw blood as she kissed him. The scrape of Mercedes’s teeth on his neck, across the delicate skin over his jugular, made him wrap his arms around her, tug her close. Deep down, under layers of artifice and denial, the pesky part of him that wanted to—to be mated, bred, to have a cursed Crest baby was trying to wake up again. Normally, at this point in the proceedings, Sylvain would flip their positions if he wasn’t on top already. This time, though, he made himself wait. The omega part of his brain was trying to flood the rest of him with, with its own cocktail of hormones, but—that was the point—he bared his neck, breathed harshly through his nose. 

Mercedes noticed though. Instead of biting down, she nuzzled his neck. It made heat wash through him, not sweet, but hot and thin. It was like blood spilling across him, through him, like poison, like his own fucking hormones. Sylvain growled, the dominant sound he’d perfected with all those omega girls, playing the role of alpha so well they never suspected. He was demanding, he was challenging, he was just the right amount of cruel to keep the poor fools guessing, to make them so eager to impress him they didn’t waste time looking at him. 

Instead of responding like one of them, though, Mercedes hummed, low and thoughtful and not at all cowed. She tangled a hand in his hair, held him down gently but immovably, and kissed a line down his jaw. Sylvain… laid there and took it helplessly as that heat washed through him again. She shifted, her skin gliding against his, and between the way it brushed against his cock and the little bloom of pain as she bit lightly at the meat of his shoulder, Sylvain let out a soft groan.

She continued like that, holding him down, alternating between soft kisses and controlled bites, until Sylvain was panting, his cock hard against his stomach. She ignored it, and her own hardened cock, in favor of kissing her way across his chest. He made a quiet sound, pathetically grateful, when she got his nipple between her fingers and pinched, hard. The pain was grounding, familiar, made his cock throb and—fuck, he was getting wet. 

The impulse, again, to flip their positions—to take control and make sure Mercedes was too busy thinking about her own cunt to worry about Sylvain’s—was there again, stronger this time. He kept his eyes pressed shut, breathed through it. He couldn’t help the way his muscles twitched under his skin though, betraying his tension, and he couldn’t do a damn thing about how Mercedes was looking at him, watching for—for something like that, apparently.

She laid full length on top of him, soft and heavy, and tangled one hand in her hair. A thin sound of approval escaped his throat as she pulled, hard enough to hurt in a satisfying way. She nipped lightly as his mouth, and he let his lips part for her. Instead of kissing him, though, she leaned over him so he could see her in spite of the angle of his neck. 

“Sylvain,” she said, “Do you want it rough, or do you want it to hurt, or both, or neither?” He blinked at her in heavy incomprehension. 

“Aren’t they the same thing?” he finally settled on. She smiled patiently and tightened the hand in his hair, renewing the pain. It was a very controlled motion. 

“This hurts, but it’s not rough. I could shove you around—I think—without actually hurting you.” That—made sense, actually, but it was too many options. Sylvain was not about to pick through that question when Mercedes was naked on top of him. She added, “Or, if I struck you, that would probably count as both.”

“That one,” he said before he could think otherwise. Dangerous heat had washed through him as soon as she’d said it, and he was already pushing her off in favor of positioning himself on the bed. Mercedes went easily, knelt quietly next to him as he braced himself on elbows and knees, legs spread. Sylvain was blushing dully, knew it probably looked terrible with his hair, but tilted his hips in invitation nonetheless. The muscles between his shoulders relaxed when Mercedes reached out to lay a hand on the curve of his ass, stroking down to his thigh. She hadn’t left, she was still here, and—

“Should I use my hand?” she asked, still stroking. Sylvain groaned. She asked so many _questions._

“Just—hurry up,” he said. She hummed her assent, and that was all the warning he got before her hand drew back and there was a sharp crack of pain as she struck him. “Ugn, _yes._ ” 

“I think I will get something to use,” she said thoughtfully, and then she just—left— Sylvain was just starting to feel disoriented but she returned almost right away, patting him just above the spot where she’d struck him a moment earlier. “Hairbrush.” He hadn’t asked, but okay. She knelt behind him and to the side, and it was easyhard to tilt his hips for her again. It was easy because Sylvain wanted this, was panting for it, but his body was trying to think for itself, trying to flinch away. The push-pull made him tremble slightly as he waited. 

Mercedes didn’t keep him waiting long. She brought the back of the hairbrush down, hard, near the first place she’d struck him. It hurt, as it was supposed to, and Sylvain grunted. She struck him again, and again, all in the same area, and before long Sylvain was drifting mentally. It was—it was hard to think about anything but the way it stung, even between blows, and the anticipation of the next one. The easyhard push-pull was strong, apprehension and anticipation tangled together in a way that had Sylvain fantastically hard and terribly wet. Mercedes spanked him again, and his groan was a high-pitched thing, straight from the hindbrain, an undeniably omega-ish noise. It managed to penetrate the merciless haze of Sylvain’s growing heat and sparked panic along his nerves. He—he couldn’t, no one could _know_. Here he was, ass in the air, _wet_ , with another person in the room. He—

Mercedes wrapped her soft, scarred hand around his larger one. He flinched and relaxed, the panicky feeling lessening but not disappearing. She didn’t say anything, just looked at him. She regarded him with such care. It was terrifying and made all the weird, damaged, self-destructive parts of Sylvain _hungry._ His chest was heaving as he tried to shrug off the moment of panic. He met Mercedes’s eyes, nodded at her to continue. She hesitated. He squeezed her hand, and she nodded and squeezed back. 

Sylvain settled his head on his bent arms, still with his ass on display, still wet. Mercedes rubbed her hand across the skin of his ass, which sounded nicer than it was. It hurt, the nerves extra-alive and angry about their treatment. She scraped her nails along, and Sylvain moaned, a cracked and broken sound of approval. He was more turned on than he could ever remember being, inarticulate desire making it hard to think about anything except his hot, swollen cunt. Mercedes kissed the curve of his ass lightly—even the part of him that was afraid to let anyone near his slick hole was having troubling making itself heard, smothered by his rising heat—and tapped the hairbrush lightly against his thigh. That was the warning. The next strike of the hairbrush was harder, drove his thoughts out of his head and left only the confused, grasping needs of the body behind. Sylvain let his back arch, a wordless request. 

She obliged him, left him stinging and aching with desire. When she laid the hairbrush to the side, Sylvain pushed himself up, threw herself at her clumsily. She caught him like she expected it, drew him close and kissed him. It was different from before: messier, hungrier. She was still soft, plump from peacetime, but Sylvain was hyperaware of how _hot_ her skin was. He wanted to touch her everywhere, wanted her warm hands to brand him somehow, felt like he was burning inside and out. She was hard too; they both were, but Sylvain was operating on limited mental power, and the sticky crawling heat in him insisted it be dedicated to his empty, aching cunt. Fuck, he was wet. 

Mercedes tugged him into her lap, kissed his mouth and his neck and his chest. Sylvain writhed against her, trying to offer up more of himself without dislodging himself from her lap. She scratched lightly at the skin of his back—a reward, perhaps—and squeezed his abused, sensitive ass. He made one of those sounds again, needy, asking. Mercedes, for her part, responded with a rumbling, creaking noise that—went straight to Sylvain’s cunt, for one thing. Fuck, he was aching and empty, uselessly slick without something inside him. The prototypical alpha noise was an aggressive one, a growl of warning or demand. The noise Mercedes made was—patient, and ultimately as impossible to defy as the passage of time. It was abiding and unhesitating, and it made Sylvain desperately want to kiss her. So he did. She kissed him back, gathering him close, and he shuddered as heat poured through him. Mercedes got both hands on his ass and squeezed again, spreading him slightly, and he groaned. Fuck, okay, alright, they were doing this.

He squirmed invitingly, trying to indicate that she should get on with things, and when that didn’t work he leaned back and gave her a pointed look. She kissed his nose but otherwise seemed to get the message, hands sliding in to tease his slick folds. Okay, okay, alright. Fuck.

“Have you done this before?” Mercedes asked. Sylvain laughed a little, and they were pressed so tightly together it shook them both. 

“Nope. Congratulations, you’ve located untapped stores of virginity inside me,” he said, stupidly. Mercedes, though, only giggled and kissed the side of his face. That wasn’t so bad. 

“Tell me if you want me to stop or slow down,” she said, “Or even if something feels weird.” Sylvain shrugged. Nice of her to say, he guessed. She kissed his shoulder, pressed her fingers into him.

Fuck, Sylvain wanted this. It was—he knew from experience that the angle like this would be weird for Mercedes, that she’d have trouble making it good, but—fuck, his body sure thought it was fine. Her fingers were barely dipping into him, but compared to the _nothing_ he’d had before—fuck. Sylvain leaned heavily on Mercedes, half-sounds pushing their way out of his throat. He—he was grinding back on her fingers, probably making it harder for her but he couldn’t control it. It was the inverse of being spanked—instead of pain that sparked arousal in its wake, it felt so good it was almost alarming. Sylvain spread his knees, tilted his hips, moaned as Mercedes pressed deeper into him. Fuck. The obscene, wet sounds as Mercedes fingered him were as arousing as they were humiliating, each feeling feeding into the other. Sylvain was shaking, riding her fingers like a whore, so wet it was dripping down her hand.

Her other hand wrapped around his waist, and she started to make that gentle alpha sound again, almost a purr. Sylvain made an answering noise—whoreish omega, begging and broken—and pressed his face against her hair. Fuck, even as shallow as she was fingering him, he was going to come. He was such a slut that having _anything_ in him was enough.

“Okay, Sylvain?” she asked, and he—fuck, words—groaned through gritted teeth. He was close, he was still so _empty_ — He cried out, mindless and offended, when she took her fingers away. He’d been so close— He was not at all mollified when she kissed the side of his head, nor when she kissed his mouth. “More, Sylvain, or less?” He groaned, an impatient and uncharacteristically small sound, and ground his hips down. Oh, fuck, her cock, her cock—

She smiled and purred as he pushed her back, not all the way down, just enough to make it easy to grip her cock, position himself over— her cock was hot and hard in his hand, and even the weight of it in his palm had him thrilling. He held her in place, pressed it against his cunt. He lost a little time to the feel of the blunt head running along his folds, teasing them both. Her hands were a patient weight on his hips, warm and gentle. He lowered himself onto her, finally, and gripped the base of his own cock as his cunt stretched around her, taking her in. He sank all the way to the base of her cock, her rumbling purr washing over him all the while.

He shuddered, and the scrap of himself that was still capable of thought wondered if this—if he was going to come, just like this, just lose himself the first time he had an alpha’s cock in him. His cunt tightened around her, made her feel bigger, and he—oh, oh, fuck. Oh, fuck, Sylvain really was nothing but a cunt, a hole to be filled. He was gasping, chest heaving, as his body tried to wring itself around her. One of Mercedes’s hands left his hip, found his cheek. He leaned into it, cupping it and keeping it there, and she was speaking, possibly had been speaking for some time. She was saying his name, and telling him that, that he was handsome and brave and good and that she—fuck—cared for him. Fuck. He did come after all, unable to do anything else in the onslaught of his own hormones and her cock and the way her words reached deep into his chest and squeezed. He slumped forward, still grinding his cunt on her cock, and made a wounded noise when she wrapped her arms around him.

He was burning up, still, and she kissed his hair, his temple, everywhere she could reach. He couldn’t speak when she asked if he was okay, did he need a break, did he want more, and instead he only pressed his face against her and whined. Finally, she braced her feet against the bed and rocked up into him. What was left of Sylvain unraveled, and he cried out in pleasure as she fucked him. He was molten, white-hot and melting against her, dangerously bright. She was cool water, taking all his heat and danger, gentling him into something different. His head was too crowded with her touch, her care, to think at all, but he braced himself above her so she could fuck into him deep and easy. He drifted, a little, as his body found more comfortable ways to hold itself. The line of his back softened, and his shoulders eased. Oh, her cock still felt so good.

“Sylvain,” Mercedes panted into his ear. There was something in her voice that tugged at him, helped guide his mind back. “Sylvain, I—I’m getting close. What do you want me to do?” Sylvain ground his hips against hers, but she whined and repeated the question. Ugh, he was going to have to find his words. 

“Do it,” he managed, “In me.” She made a noise of assent and grabbed his hips, guiding him off—“No, I mean—do it,” he repeated. His heat would break faster if she knotted him, and even, even beyond that, he—“ _Mercedes._ ” He needed her to understand. 

“Sylvain,” she said, and her voice was so strained it broke a little on his name. She sounded worried. “Sylvain, my—my body wants to knot—”

“Yes.” With relief he ground himself on her again, shuddering even at the thought. “Yes, now. Mercedes.” That, thankfully, seemed to be enough. She moved her hands off his hips, settled one on his back and cupped the back of his head with the other. Sylvain was beyond caring what he sounded like, moaned high and needy as she fucked him. When her knot finally expanded in him, the sound he made was almost a wail, catching and breaking and continuing. He’d assumed, privately, that being knotted would hurt, but—he was just full, full, impossibly full. There was a satisfaction in taking his body exactly to the limit of what it could do and keeping it there, and he came and came and came.

When he came to, as it were, his ability to think flowing back as easily as it had never left, Mercedes was kissing his face. Her lips were soft on his forehead, his cheek, the bridge of his nose. That was nice. He shifted a little—gasped as an aftershock shook him—and pressed their mouths together. Mercedes kissed him with care and—yeah—affection. He brushed her hair out of her face just for an excuse to touch her a little more. She smiled, kissed him again. The slight motion jolted him, sent another little aftershock shivering through him—both of them, if her dazed expression was anything to go by—and he breathed comfortably through it. Something in his chest was glowing, not burning, and it was spreading warmth throughout the rest of him. In relative quiet, they laid together. It reminded Sylvain a little of being outdoors after a storm had passed. The drama and noise an echoing memory, the hush of the landscape, the way the light was sharply beautiful before gentling back to the same familiar day. Now that they were less—distracted, the comfortable sounds of the outside world started to filter back in. Out there, everything was waiting. Sylvain shifted to lie a little more comfortably on Mercedes, and she threaded warm fingers in his hair. As far as he was concerned, it could wait a little longer.

**Notes for the Chapter:**

> If you would like more Sylvain, I have [you, secret as the moon](https://archiveofourown.org/works/28607118) which is Sylvain/Dorothea, rated E, featuring pegging, feminization, verbal degradation, and some light praise kink  
> There is also [in vino veritas (yo annette’s wasted)](https://archiveofourown.org/works/25759033) for a silly fluffy ensemble piece (rated G), in which the Blue Lions, in classic teen fashion, get drunk and dish on their mutual crushes on the Professor.  
> And there is [Five times the Blue Lions were normal about food (and everyone else was weird)](https://archiveofourown.org/works/25855357) which is a cultural study of food in the Kingdom. (rated G) _The Holy Kingdom of Faerghus is a cold, rocky place with harsh winters and short summers. It can be hard to grow enough for everyone._ Love speaks through food, _that’s how the saying goes. / The importance of food as it pertains to the Blue Lions._

**Author's Note:**

> Will there be more of this 'verse someday? *stares at page of notes about other Blue Lions in this 'verse* God, I hope so. This fic is marked "complete" but if you wanna get notified if there's more, hit subscribe!
> 
> I would like to thank my dice, who gave me 3 omegas in a row, and parrotfish, for being sequentially hermaphroditic. God, I love ABO AUs but are we playing with the formula enough?? *crawls back into dumpster*  
> ==  
> Comments are a delight!


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